'Bitter' in the Bible

Those of you who are making justice taste bitter, and who have thrown righteousness to the ground:

Can horses run on rocky cliffs? Can one plow the sea with oxen? Yet you have turned justice into a poisonous plant, and the fruit of righteous actions into a bitter plant.

And I will turn your feasts into mourning, and all your songs into lamentation; and I will bring up sackcloth upon all loins, and baldness upon every head; and I will make it as the mourning of an only son, and the end thereof as a bitter day.